Population Pharmacokinetic Analysis of Dexmedetomidine in Children using Real-World-Data Obtained from Electronic Health Records and Remnant Clinic Samples
Dexmedetomidine is commonly used as part of intraoperative anesthetic management and for sedation and pain control after surgery in children. Dexmedetomidine infusion dose is typically given on a fixed weight basis with titration to achieve sedation goals while avoiding potential toxicities. Pharmacokinetic (PK) studies are useful for accurate prediction of the individual dose required to achieve sedation and analgesia goals without toxicity, but lack of PK data is a challenge in precision dosing for pediatric populations. In this study, population PK models were developed using a nonlinear mixed-effects modeling approach and used to explore the relationship between PK profile and clinical, demographic, and genotype covariates. A simulation study was used to demonstrate the impact of important covariates on concentration using a fixed weight dosing scheme. Our final study population included data from 354 patients age 0 to 22 years (median age 16 months). In the final two-compartment model with fixed allometric weight scaling we found significant effects of both age and UGT2B10 genotype. The population PK parameter estimates (95% confidence interval) for a standard 70 kg weight were clearance 22.3 (18.3 - 27.3) L/hr, central compartment volume of distribution 133 (112 - 157) L, intercompartmental clearance 24.1 (19.4 - 29.9) L/hr, peripheral compartment volume of distribution 5230 (3310 - 8260) L. Our study provides support for the feasibility of using real-world data obtained from EHRs and remnant samples to perform population PK analysis for groups of patients where traditional PK studies are challenging to perform. Inclusion of UGT2B10 genotype in the model significantly improved the model fit, but the effects were not large enough to impact clinical dosing.